Theory:

Alliteration is the occurrence of the same sound, if not a letter, at the starting of two or more words in a single line, in a poem.
1. The slender smiling girl.
2. The song of sweet birds.
3. Black bug bit a bear.
4. Practise the piano.
5. Feel the phone on your face.
What are the uses of alliteration?
 
1. It creates a rhythm, similar to rhyming words.
2. It emphasizes the importance of phrases.
3. Mostly used in tongue-twisters.
Alliteration used in the poem "A Slumber Did My Spirit Seal"
A l slumber did my spirit seal—
I had no human fears.
She seemed a thing that could not feel
The touch of earthly years.
No motion has she now, no force—
She neither hears nor sees,
Rolled round in earth’s diurnal course
With rocks and stones and trees.
 
                            ~ William Wordsworth